Clamp



Oct. 21, 1952 c. M. wooDwARD CLAMP Filed May 17, 1946 INVENTOR. CHAR/.E5 M. WOODWARD A T TORNEI/S Patented Oct. 21, 1952 UNITED STATES PATENT OFFICE" CLAMP Charles M. Woodward, Pasadena, Calif.

Application May 17, 1946, Serial No. 670,474

9 Claims.

l ,This invention is concerned with clamps, particularly pinch clamps for control of fluid flow in resilient tubing. In its preferred form it finds ,application in control of the flow of anesthetics While these are being introduced intravenously l and provides an improved clamp that assures positiveand convenient ow control without leakage when complete shut-off is required. Moreover, the clamp is so constructed that it can be slid on or off the tube laterally, so that it can be placed in operating position even when the ends of the tube are not free and do not permit placing the Aclamp by sliding over one free end.

The control ofthe flow of an anesthetic being administered intravenously is accomplished customarily by a pinch clamp placed on a rubber tube or the like through which the anesthetic ows from a head tank or burette toa syringe yor hypodermic needle. The total quantity administered and the rate of administration must be controlled accurately, and the stoppage or interruption of ow at the appropriate time should be positive, since leakage may mean that excessive anesthetic reaches the patient, with serious and possibly fatal result. Clamps heretofore available have not been entirely satisfactory, and

in many instances serious `accidents have occurred due to the fact that iioW of the anesthetic continued, though at a slow rate, after the pinch clamp was supposedly closed. Furthermore, pinch scribed purpose and similar uses do not permit the clamp to be placed on the tube or removedtherefrom except over a free end. This is a se- V clamps heretofore available for the above derious objection, because after both ends of thel the tube will be properly pinched and will be completely closedas desired. Moreover, in the prebe adjusted to any predetermined amount, so that when necessary a regulated amount may be run at predetermined and constant rate. Thirdly, the`pinch clamp of my invention is so constructed that the clamping means maybe swung to one side to insert the tubing at any point along the length thereof.

.l In summary, my invention contemplates the J,.ombinationin a pinch clamp which comprises ,2 *y l a iirst clamp member having a clamping surface on one end and a bore running throughr it to the other end, a second `U-shaped clamp member having a long leg and a short leg substantially parallel to each other with a clamping surface in between, the long leg being slidably` and rotatably mounted in the bore and the short leg being slidably mounted in a second bore in the rst member, springing means for pressing the two clamping surfaces toward each other, and means attached to the long leg and projecting outside the rst member at the end opposite its clamp-ing surface for rotating the long leg and sliding it suiiiciently to move the short leg out of the second bore.

In my preferred structure, the springing means is a helical spring mounted within the first member, preferably in the irst bore and coaxial with the long leg. v

The means for rotating and sliding the long leg in its bore preferably is a button attached to the free end of the long leg, i. e. the end opposite the clamping means.

4In my preferred structure, I provide a light helical spring and also a heavy helical spring disposed coaxially with each other and with the long leg in the iirst bore. A light spring gives adequate movement of the clamp for its intended purpose, and it is compressedi'lrst. Upon further sliding of the long leg the heavy helical spring is ,compressed sufficiently that the short leg may be 'slid from its `bore and swung to one side, so that tubing are engaged, for example, one end being vferred form of my pinch clamp, the opening may `the tubing can be inserted in or removed from the clamp. Preferably, the light helical spring and the heavy helical spring are placed end to end in the rst bore, although they may be placed one over the other and coaxially.

In one type of the clamp of my invention, I provide adjustable stopping means for regulating the distance to which the clamping surfaces may approach each other. It permits the clamping `surfaces to be `adjusted to maintain` a constant ow through the` tubing if and when such is desired. The adjustable stopping means may comprise a threadedbushing through which one leg `of the second clamping member passes coaxially. A control Wheel is journaled in the nrst member `and threaded around the bushing and the bush- -ing is so disposed that it moves longitudinally but does not turn. By turning the wheel, the longitudinal movement of the bushing is accomplished and controlled. f

In a further modification of my invention, I provide dual clamps, one of which tends toire- `xnainclosed and the other of which tends to rejunction with the accompanying drawings in Which Fig. 1 is a side elevation of one form of the clamp of my invention;

Fig. 2 is a sectional elevation of the clamp'l of Fig. 1, taken along the line 2-2;

Fig. 3 is a side elevation of a modied' forni of the cls .mpI of Fig. 1, provided with one type of adju stable stopping.rieans'gH is a sectional elevation taken through' the clamp of Fi'gp alone? the line 4-45 Y l VFig. 5 is a bottoni View oftheclamp of Figs.' 3 and 4,Y illustrating the use of an adjust-able bushing asa stopping r'iear'is;

Fig. is -a sectional elevation of a further modification of the clamp' of the invention provided4 with aotherftype of stopping means;

,Figs'l is a sectional elevation through the clamp of Fie. s, taken aion'gthe iin@ if-i and inustrati'ng theuse of two' helical springs, one light and onehavyg Fig. 8 is a. plan view f the adj`l. 1sting nut of thestoppingmeans of Figs, 6 and'';

Ffig 9 is' a sectional elevationv through a dual clamp mechanism of my invention adapted to control two tubes; Y Y y Fig. 10 is a fragmentary bottom View' of a portion of the clamp of Fig'. 9]; and AFig. vl1 illustrates a modication of the `clamp of Figg and 10.

Referringto Figs. 1 and 2', itwill b evob'served thattheclamp comprises a main member or body 2 .l .h`avi 'ng tw transverse branches lor lugs 251A, 211B, adapted to be grasped by the nger`s. The lowerend of the main member has af flat' clampings urfacef As shown Vin Fig. 2 the body has'a central bore'V ZSfthbug'h which passes the long leg 254A ,of aHUls'liaped clampingineinber iliade of; bent rod ofA circular cross section. The 4long iegiits the lower' pair. of tiieoyiindrioai boro, andcan be slid and rotated therein. The other leg 24B ofthe U member' is shorter but parallel to the long leg and passes through a second bore 25 in the outer portion of the body.

. 'Ihe ,central bore has' an' enlarged upper portionwithin which a helical spring 26 isrdisposed concentrically around the' long leg. v The upper endofthe longleg is screwed into a' buttony 21 .whchg has an enlarged upper portion ana a lower cylindrical shank portion" 21A of approximately the same diameter as the enlarged portion of the bore. The length ofthe lower por'- Ationgof the button is such thatwhen the button ifs compressed4 completely against the' mainmem- Yber- (which comprises the spring`- between the button and the bottom of the enlarged or"uppe`r portionof the bore), the short leg of the U .comes outof itsbore 2'5 andisfree to' be rotated to oiie side. 'riie rest of tiiotime the; spring itends to hold the short leg in its' bore; compressinea piece of tubing or the like (not shown) held betweenthe claipiig'- surfaces, i; e. the

bottom of the body and the bottomv of the u.

The apparatus of Fig. 1 is simple, and yet highly eifective. The body is so designed as to t between two fingers of one hand while the thumb compresses the button and opens the clamp. A slight pressure on the button is sufficient to open the clamp and an enclosed tube (not shown). Additional pressure applied on the button opens the clamp to the point where the short leg vcan be slidout of its bore, for example by rotating the button, sbthatl the enclosed tube can be removed.

l The two clamping surfaces are such that the tube cannot become kinked or only partially compressed, for if the tube is enclosed its entire cross section must be compressed between two parallel straight surfaces.

When no pressure is applied to the button, the spring causes the clamp to remain closed thus effectively shutting off an enclosed tube.

Referring now to Figs. 3, 4and 5 it will be observed that the structure illustrated is substantially identical to that of Figs.V l and 2 like parts being indicated by like numerals, but with the following. additions. The long leg of the U instead of passing directly throughv a small lower bore'2 instead passes through a bushing 39 which slides longitudinally in the bore. The` bushing is at on one side 3|, as shown in Fig.. 5, and

the" remaining cylindrical surface l tl 11ea.ledv to t the interior thrcegdlhgfbalihar iusting wheel 32. This adjusting' Wheel` is placed in a slot 33 through which the bushing passes in an unthreaded bore having one flat side (fse'e Fig. 5)' to prevent the bushing from turning.. By adiusting the wheel', the bushing may be turned upward or downward.- The lower portion ofthe bushing bears on the inside or bottom of thev U and when the wheel is screwedsufciently it will prevent the clampv from closing completely Ihus the clamp of Figs. 3, 4 and 5 may be ad; Justed for any set opening. This is particularly useful when a drip method of administering an anesthetic or other reagent is employed.

Passing to a consideration of Figs. 6, 7 andv 8 it will be observed that the mechanism illustrated thereby is like that of Figs. 1 and '2. However nelig. G tihe clamp is shown partly compressed' par y openwith a hose 3` A" claniilping surfaces. 5 between *the T e clamp is held in this osition b-v of an adjustable stop comprising ,a'yvlgilila threaded shank 36 the lower end off whichy is threaded into the bodyinside and parallel to the bore 25 in whichv the snort ieg of the u-momber slides. A threaded wheel 3l is screwed onto the shank and covers the bore 25 except when a vcutout segment 38 (see Fig. 8)' is turned over the bore. 'lhe wheel may be adjusted as to height by turning it on the shank, and by placing the cut-out segment out of the line of the lower leg, the wheel acts as a. stop and prevents' the clamp from seating completely. lHowe r' 'a slight turn or the wheel in either directie viii permit theshort end of the u to Snap upthfugh th ll-llll SglI f Wheel SO' tlltktlle clamp is free to coni resz off, its spring.. A p s the hose to the limit Another important distinction between' params of rigs. s and 7 and that of Fieshid zwisthe fact that it is provided .with two i'ieiioai springs, an upper helicalspririg 3'9 of light gauge (so thatit is easily compressed)v anda lower and somewhat shorter and coarser helical vspi'ri'ng I0 which is compressed with somewhat more' difficulty, bf`1`hespring 3 9 is compressed liirs't' and is long enough to accommodate the normal'otion of the clamp. However, when it is necessary to open the clamp to insert or take out a tube, the button is pressed until it almost touches the body of the clamp whereupon the lower and heavier spring is compressed so that the short leg of the U can be swung out of its bore.

It will be apparentthat the springs 39, 4D may be reversed in position and that two telescoped springs. one coarse and one fine, can also be employed. However, the structure illustrated is preferred. I i

As I have already indicated, there are certain methods of intravenous anesthesia which require the addition of two reagents in series. The clamp of Figs. 9, 10` and 11 is adapted to this purpose. The left side of the clamp is substantially the same as that of Figs. 1 and 2, like parts being indicated by like reference characters. However, the shank or center of the main clamp body 2li is thicker, so as to accommodate an extra bore 4| parallel to the first bore` 23. `In the upper or enlarged portion of this bore is a helical spring 42 which normally is under slight compression as is its companion spring 26 in the other bore. Through the spring and through the bore passes an additional clamping member 43 having a long upper leg 43A and a short lower leg 43B, joined by a third portion 43C, transverse to both legs. Thus the clamping member 43 is in general S-shaped rather than U or L-shaped,

and may be made by bending a cylindrical rod. The lower leg. it will be observed, is shorter than the upper leg and parallel to it but extends in the opposite direction from the central piece 43C. It is held by the spring in the opposition shown in the sketch so thata flexible tube 44, placed in the clamp between the S-shaped member and an extension 45 on the bottom of the clamp is normally open. A long button 4t is threaded onto thetop of the S-shaped clamplng member, the lower cylindrical shank 46A of this button beingof the same diameter as the enlarged upper portion of the bore.

The L-shaped extension 45 on the lower part of the clamp is formed integrally with the main clamp body 2il and its bottom branch is parallel to the central portion 43C of the S-shaped member so that there is a slot with parallel sides between the body proper and the bottom of the extension.

The lower leg 43B of the S-shaped member is adapted to slide in a bore 41 in a bushing 48, which is in general constructed like the bushing of the apparatus of Figs. 3, 4 and5, being at on one side as shown in Fig. l `and threaded on the rest of its circumference. The bushing 48 is located in a bore in the` extensionA 45 on the bottom of the clamp. The bore is slightly larger than the bushing so that the bushing is free to move up or down inside the bore. An operating wheel 49 is threaded around the bushing and placed in a horizontal slot U in the lower extension. By turning the operating wheel, the bushing may be screwed down and depressed sufficiently that the lower leg of the S-shaped member may be swung to one side by turning the upper button to permit the removal of the leg 43B.

In the operation of the apparatus of Figs. 9 and 10, liquid is iirst run through the tube 44 (mounted in the right hand side of the clamp) in desired amount and then the button 46 is compressed until no further movement is possible. This effectively closes the tube 44. Further movement of a thumb applied to the button 4E will press the other button 21 and cause it to move nearer the body 2U so that the attached U-shaped clamping means 24 is opened, thereby permitting a tube 52 to open so that flow through this tube is established. The whole operation can be conducted with one hand, one thumb manipulating both buttons.

In the apparatus of Fig. 9 the bushing., and its accompanying operating wheel, do not serve the same function as the bushing and operating wheel in the apparatus of Figs. 3, 4 andi. On the contrary, the bushing and wheel in the Vapparatus of Figs. 9 and 10 are adapted to lock the S-shaped member in operating position after the tube has been inserted.

The bushing and operating wheel employed as a locking means in the apparatus ofV Figs. l9 and 10 may be placed in another position.` This is illustrated in Fig. l1, wherein it will be `seen that another bushing (it stands vertically in the main frame above the horizontal portion of the S-member. This bushing is like that of Figs. `9 and 10, iat on one `side and threaded on` the rest of its circumference and slides in a vertical bore which likewise is flat on one side. An-operating wheel 6I is threaded around the bushing in a horizontal slot 62. By turning the operating wheel, the bushing may be `screweddown so that the lower leg 43B of the S-member is locked in a bore 63 in the extension 45 ofthe main frame or member. Thus the lockingmeans of Fig. 1l is substantially the same aswth that of Figs. 9 and 10, the principal difference being that itis disposed in another position.

It should be noted that the lower extension of the clamp of Figs. 9 and 10 is provided with a slot 'lil to permit the S-shaped member to be slid up into the bore 4l of the apparatus. This aids in assembly.

I claim: i

1. In a pinch clamp, the combination which comprises a rst clamp member having a clamping surface on one end and a bore running through it to the otherend, a second U-shaped member having a long leg and a short leg -substantially parallel to each other with a clamping surface in between, the long` leg being `slidably and rotatably mounted in the bore, and the short leg being slidably mounted in a second bore in the irst member, the clamping surface of `the U-shaped member being located in the projection of the clamping surface oi the rst clamp member, springing means for pressing the 4,two clamping surfaces toward each otheryandmeans attached to the long leg and projecting outside the first member at the end opposite its clamp-` ing surface for rotating the long leg and sliding it sufficiently to move the short leg out of the second bore.

2. In a pinch clamp, the combination which comprises a iirst clamp member having a clamping surface on one end and a bore running through it to the other end, a second Ul-shaped member having a long leg and a short leg substantially parallel to each other with a clamping surface in between, the long leg being slidably and rotatably mounted in the bore, and the short leg being slidably mounted in a second bore in the first member, the clamping surface of the U-shaped member being located in the projection of the clamping surface of the first clamp member, a helical spring mounted within the first member for pressing the two clamping surfaces to each other, and means attached to the long leg and projecting outside the rst member 7 at the* erro deposite its Eating' the long leg and sliding itv su'iciently' to move' the' short leg out of the second bore'.V

35. n a pinch clamp, the combination which comprises a first clamp member' having a clamping surface on one end anda4 bore running through it to the other' end, a second Lit-shaped Inefnber having a long leg and a short leg substantially parallel to each other with a clamping Sl'rfaoe in between, the spacing between the clamping surfaces' of the rs't andi secondi mein bers being substantially equal throughout the length of' the surfaces, the long leg being vslidabl'y and rotatablymounted in the bore, and the-short leg being slidably mounted in a second bore in thenrst`r mem-ber, the clamping surface of the Ll-'sh-aped member being located inthe projection of` the clamping' surfaceI of the rst clamp member, a helical spring mounted Within the rst' member coaxial with the long leg! for pressing the two clamping surfacesto each other, and means attached to the long leg and projecting outside the rst member at the endv opposite its clamping' surface for rotating theA long' leg and sliding it sufficiently to move the short legA out of the second bore.

4. Apparatus according to claim 3y which the means -for rotating and sliding ther long leg is a buttonattached to its free end.

5. In a pinch clamp, the combination which comprises a first clamp member having a clamping surface on one end and a bore running through it to the otherv end, a` second U-shaped member having a long leg and a short leg substantially' parallel to each other' with a clamping surface in between, the long leg being slidab'ly and rotatably mounted in the bore, and the short leg being slidably mounted ina second bore in' the rst member, the clamping surface of, the U-shaped member being located in the projection of the olamping surface of the first clamp member, a light helical spring and a` heavy helical spring disposed coaxial with the long leg in the rst bore for pressing the two clamping surfaces to each other, and means attached to the long leg and projecting outside the rstmember at the end opposite its clamping" surface for rotating the long leg and sliding it sufficiently to move the short leg out' of the second bore.

6. Apparatus according toclaim 5 in which the two springs are placed end to end in the first bore.

7. In a. pinchV clamp, the combination which corn'prisesv a first clamp member having a clamp ing surface on one end and a bore running tlnough it to the other end, a second U-shaped member' having al longV leg and a short leg suba'mpi-rlg surfacefo'r ro" s'iantiall-yA` parallel to each other with a'. clamping s'iir'faoe in between, the long leg being slidably and rotatably mounted inthe bore, and the short leg' being slidably mounted in a second bore in the'A rst member", spring means for' pressing the two clamping surfaces toward each other, means attached to the long leg and projecting outside the' first member on its end opposite its ciampi ing surface'for rotating the long leg and sliding it suiciently to move the short leg out of the second bore, and adjustable stopping means for regulating the distance to which the two clamping- 'surfa'c'es may approacheach other.

8-. Apparatus according to claim 7 in which the adjustablestopping means comprisesv a threaded bushing through which a leg of the second ineinber passes co'axially, and a wheel journaled in the rst member and threaded around the bushing'.

9. Ina pinch clamp, the combination which comprises a rst clamp member having a clamping surface on one end and a bore running through it to the other end, lug-s extending trans* versely on each side of the bore adjacent that other end, a second U-shaped member having along leg" and a short legsubstantiallyv parallel to each other with a clamping. surfacein between, the clamping surfaces of the first and second members having mating contours,- the longleg being slidablly' and rotatablymounted inthe bore, and the short leg being slidably mounted in a second bore in the first member, the clamping surface of the U-shaped member being located in the projection of the clamping surface of the rst clamp member', spring means forv pressing the two clamping surfacestoward each other, and means attached to the long leg and projecting outside" the nrst member at said other end for rotating the long leg and sliding it sufficiently to move` the short leg out of' the second bore. v

CHARLES M.. `WO`ODWA-RD-n REFERENCES CITED The following references are of recordv in the le of thisv patenti UNITED STATES PATENTS Wallace' en 1e.- May 1.8, 1943 

